Physics

On the basis of band theory of solids the semiconductors have _____________________?

Options:

• A. A party filled valence band and totally empty conduction band
• B. A completely filled valence band a totally empty conduction band and a very wide forbidden band
• C. A completely filled valence band a partially filled conduction band and a narrow forbidden band
• D. A partly filled valence band a totally empty conduction band and a wide forbidden band

View Answer

C. A completely filled valence band a partially filled conduction band and a narrow forbidden band

Many of the semi conductors are crystals of the type__________________?

Options:

• A. Face centred cubic
• B. Body centred cubic
• C. Simple cubic
• D. All of the above

View Answer

A. Face centred cubic

Very weak magnetic fields are detected by___________________?

Options:

• A. Squids
• B. Magnetic resonance imaging (MRI)
• C. Magnetometer
• D. Oscilloscope

View Answer

A. Squids

Holes can exist in____________________?

Options:

• A. Conductors
• B. Insulators
• C. Semi conductors
• D. All of the above

View Answer

C. Semi conductors

Energy needed to magnetize and demagnetize is represented by _________________?

Options:

• A. Hysteresis curve
• B. Hysteresis loop area
• C. Hysteresis loop
• D. Straight line

View Answer

B. Hysteresis loop area

In a semiconductors the charge carriers are ___________________?

Options:

• A. Holes only
• B. Electrons only
• C. Electron and holes both
• D. All of the above

View Answer

C. Electron and holes both

What is the SI unit of modulus of elasticity of substance ?

Options:

• A. Nm-2
• B. Jm-2
• C. Nm-1
• D. Being a number it has no unit.

View Answer

A. Nm-2

The net charge on n-type material is____________________?

Options:

• A. Positive
• B. Negative
• C. Both positive and negative
• D. Neutral

View Answer

D. Neutral

A rubber cord of cross-sectional area 2cm2 has a length of 1m. When a tensile force of 10N is applied the length of the cord increases by 1cm. What is the youngs modulus of rubber ?

Options:

• A. 2
• B. 5
• C. 0.5
• D. 0.2

View Answer

B. 5

Magnetic force acting on a unit positive charge moving perpendicular to the magnetic field with a unit velocity is called____________________?

Options:

• A. magnetic flux
• B. magnetic field intensity
• C. magnetic induction
• D. self inductance

View Answer

C. magnetic induction